Calculate the expected value of a discrete outcome list given matching probabilities.
| Expected value | – |
Use this calculator for a discrete random payoff: a lottery, a game, or any list of outcomes with probabilities. The expected value is the probability-weighted average, the long-run mean if the same experiment is repeated.
The formula is: EV = Σ xᵢ pᵢ. Paste outcomes and probabilities in the same order, one probability per outcome. Probabilities should add to about 1 (a tolerance of 0.02 is allowed). With outcomes 1, 0, −1 and probabilities 0.3, 0.4, 0.3, EV = 0.
A positive EV is not a promise of a win on one trial. Negative probabilities are rejected. This is not a continuous density and does not compute variance.
Outcomes: Numeric payoffs, comma- or space-separated.
Probabilities: Matching probabilities, same length, each at least 0, summing to about 1.
Expected value: Probability-weighted mean of the outcomes.
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